In an endoscope apparatus including a color conversion process such as LUT, a set value of a conversion parameter is generally determined in advance; when a type of an input image and an environment such as illumination change, a user manually switches the set value and the like. Since the set value is manually set in advance, it is difficult to set an optimal parameter according to a situation, and it is difficult to obtain an output image adjusted to have an optimal color by this, so that it is required to automatically obtain an image with high color discrimination.
In response to such a situation, there are suggestion to change color reproduction according to a light source type (refer to Patent Document 1) and suggestion to switch a system color tone for each organ being observed (refer to Patent Document 2).